To determine the incidence of hepatitis in prospectively followed open heart surgery patients receiving blood that has been prescreened for Hepatitis B (HBV), Hepatitis C (HCV) and Human Immunodeficiency (HIV) Virus markers. Hepatitis compared with that of identically followed patients in previous studies in which no attempt was made to exclude blood with HCV or HIV markers. In previous studies blood units with elevated ALT or anti-HBc were more frequently associated with recipient hepatitis than units with normal values. Cases of hepatitis will be serologically assessed for virus etiology and patients will be carefully followed for the development of chronic hepatitis. This study which had enrolled only NIH open heart surgery patients has now been shifted to Georgetown University in light of the discontinuation of the NIH heart surgery program. If support can be obtained, the study will be expanded to include Children's Hospital and the Washington VA.